I have changed my mind about the general validity of the mechanical worldview that underlies the modern scientific understanding of natural processes. Trained in biology and mathematics, I have used the scientific approach to the explanation of natural phenomena during most of my career. The basic assumption is that whatever properties and behaviours have emerged naturally during cosmic evolution can all be understood in terms of the motions and interactions of inanimate entities such as elementary particles, atoms, molecules, membranes and organelles, cells, organs, organisms, and so on.

Modelling natural processes on the basis of these assumptions has provided explanations for myriad natural phenomena ranging from planetary motion and electromagnetic phenomena to the properties and behaviour of nerve cell and the dynamic patterns that emerge in ant colonies or flocks of birds. There appeared to be no limit to the power of this explanatory procedure, which enchanted me and kept me busy throughout most of my scientific career in biology.

However, I have now come to the conclusion that this method of explaining natural phenomena has serious limitations, and that these come from the basic assumptions on which it is based. The crunch came for me with the "explanation" of qualitative experience in humans and other organisms. By this I mean the experience of pain or pleasure or wellbeing, or any other of the qualities that are very familiar to us.

These are described as "subjective", that is, experienced by a living organism, because they cannot be isolated from the subject experiencing them and measured quantitatively. What is often suggested as an explanation of this is evolutionary complexity: when an organism has a nervous system of sufficient complexity, subjective experience and feelings can arise. This implies that something totally new and qualitatively different can emerge from the interaction of "dead", unfeeling components such as cell membranes, molecules and electrical currents.

But this implies getting something from nothing, which violates what I have learned about emergent properties: there is always a precursor property for any phenomenon, and you cannot just introduce a new dimension into the phase space of your model to explain the result. Qualities are different from quantities and cannot be reduced to them.

So what is the precursor of the subjective experience that evolves in organisms? There must be some property of neurones or membranes or charged ions producing the electric associated with the experience of feeling that emerges in the organism.

One possibility is to acknowledge that the world isn't what modern science assumes it to be, mechanical and "dead", but that everything has some basic properties relating to experience or feeling. Philosophers and scientists have been down this route before, and have called this pan-sentience or pan-psychism: the world is impregnated with some form of feeling in every one of its constituents. This makes it possible for the evolution of complex organised beings such as organisms to develop feelings and for qualities to be as real as quantities.

Pan-sentience shifts science into radically new territory. Science can now be about qualities as well as quantities, helping us to recover quality of life, to heal our relationship to the natural world, and to undo the damage we are causing to the earth's capacity to continue its evolution with us. It could help us to recover our place as participants in a world that is not ours to control, but is ours to contribute to creatively, along with all the other diverse members of our living, feeling, planetary society.